1. Field of the Invention
This invention relates to a crash bar assembly for a vehicle chassis adapted for an auxiliary equipment carrying mode with the auxiliary equipment projecting rearwardly therefrom. It also relates to a crash bar assembly for a vehicle chassis to accommodate the carrying of loads generally projecting rearwardly therefrom and further relates generally to a crash bar assembly for auxiliary equipment which may be carried on the rear of a vehicle chassis so that it projects rearwardly therefrom to overhang the rear of the vehicle chassis.
2. Background Information
One of the principal problems in relation to such auxiliary equipment, for example, forklift trucks which are regularly carried on the rear of a vehicle chassis is that crashes do occur when they are on the chassis and they can cause considerable damage by being shifted relative to the truck chassis. Such forklift trucks are often called "piggy-back forklifts". There is thus a need to overcome this problem.
There are various regulations in force in relation to such crash bars, often referred to as rear underrun bumpers or rear underrun protection devices, these bumpers must be fitted as near as possible to the rear of the vehicle and the lower edge must not be more than 550 mm from the ground. Further, the crash bar or bumper must extend to within at least 100 mm from the outermost width of the axles and must not, in any case, extend beyond the width of the rear axle when measured across the outermost face of the tires. When auxiliary equipment is carried in piggy-back fashion, such as, for example, a piggy-back forklift, the forklift or other auxiliary equipment extends beyond the crash bar or underrun bumper so no matter how efficient and correctly fitted such a bumper is, it is of relatively little use when the vehicle is in the auxiliary equipment carrying mode. This equally applies to any projecting load.
Certain work has been done in relation to these crash bars such as, for example, described in European Patent Specification No. 0 299 357 (Daimler-Benz AG) which discloses a crash bar which can be raised or lowered relative to the vehicle.
However, the prior art does not disclose crash bar assemblies that will overcome the problems inherent in the present constructions which are generally speaking either totally rigidly secured adjacent the rear of a vehicle chassis or are given some minor or limited movement such as for example described in U.S. Pat. No. 4,247,138. None show a crash bar that could be used to achieve the objects of the present invention.